Coherent magnetic reversal in half-metallic manganite tunnel junctions

2000 ◽  
Vol 77 (23) ◽  
pp. 3803-3805 ◽  
Author(s):  
Moon-Ho Jo ◽  
N. D. Mathur ◽  
J. E. Evetts ◽  
M. G. Blamire
Keyword(s):  
Tunnel Junctions ◽  
Magnetic Reversal ◽  
Half Metallic

Magnetism and Spin Tunneling in Nanostructures

1997 ◽  
Vol 491 ◽  
Author(s):  
Alexander Bratkovsky
Keyword(s):  
Spin Polarization ◽  
Tunnel Junctions ◽  
Iron Group ◽  
Defect States ◽  
Resistance Change ◽  
Half Metallic ◽  
Spin Tunneling ◽  
Inelastic Tunneling ◽  
Resonant Tunnel ◽  
General Method

ABSTRACTIn the present paper different tunneling mechanisms in conventional and half-metallic ferromagnetic tunnel junctions are analyzed within the same general method. Theoretically calculated direct tunneling in iron group systems leads to about a 30% change in resistance, which is close but lower than experimentally observed values. It is shown that the larger observed values of the TMR might be a result of tunneling involving surface polarized states. We find that tunneling via resonant defect states in the barrier radically decreases the TMR (down to 4% with Fe-based electrodes), and a resonant tunnel diode structure would give a TMR of about 8%. With regards to inelastic tunneling, magnons and phonons exhibit opposite effects: one-magnon emission generally results in spin mixing and, consequently, reduces the TMR, whereas phonons are shown to enhance the TMR. The inclusion of both magnons and phonons reasonably explains an unusual bias dependence of the TMR.The model presented here is applied qualitatively to half-metallics with 100% spin polarization, where one-magnon processes are suppressed and the change in resistance in the absence of spin-mixing on impurities may be arbitrarily large. Even in the case of imperfect magnetic configurations, the resistance change can be a few 1000 percent. Examples of half-metallic systems are CrO2/TiO2 and CrO2/RuO2, and an account of their peculiar band structures is presented. The implications and relation of these systems to CMR materials, which are nearly half-metallic, are discussed.

scholarly journals Use of Half Metallic Heusler Alloys in CoFeB/MgO/Heusler Alloy Tunnel Junctions

2013 ◽  
Vol 49 (7) ◽  
pp. 4379-4382 ◽  
Author(s):  
P. J. Chen ◽  
G. Feng ◽  
R. D. Shull
Keyword(s):  
Heusler Alloy ◽  
Tunnel Junctions ◽  
Heusler Alloys ◽  
Half Metallic

Enhanced conductance blockade due to Pauli exclusion in tunnel junctions with half-metallic electrodes

2009 ◽  
Vol 373 (31) ◽  
pp. 2782-2785
Author(s):  
T.-H. Kim ◽  
X.-G. Zhang ◽  
J.F. Feng ◽  
X.F. Han ◽  
A.P. Li
Keyword(s):  
Tunnel Junctions ◽  
Half Metallic ◽  
Metallic Electrodes

scholarly journals Structural and Microanalytical Studies of CrO2 Thin Films on c-Sapphire by High Resolution Electron Microscopy Methods

2008 ◽  
Vol 14 (S3) ◽  
pp. 47-48
Author(s):  
M.I. Ortiz ◽  
P.M. Sousa ◽  
C. Ballesteros ◽  
A.J. Silvestre ◽  
L.F. Cohen ◽  
...  
Keyword(s):  
Room Temperature ◽  
Tunnel Junctions ◽  
High Resolution Electron Microscopy ◽  
Chromium Dioxide ◽  
Recording Industry ◽  
Insulating Layer ◽  
Half Metallic ◽  
Spintronic Devices ◽  
Resolution Electron ◽  
Spin Polarized

Chromium dioxide (CrO2) has been extensively used in the magnetic recording industry. However, it is its ferromagnetic half-metallic nature that has more recently attracted much attention, primarily for the development of spintronic devices. CrO2 is the only stoichiometric binary oxide theoretically predicted to be fully spin polarized at the Fermi level. It presents a Curie temperature of ∼ 396 K, i.e. well above room temperature, and a magnetic moment of 2 mB per formula unit. However an antiferromagnetic native insulating layer of Cr2O3 is always present on the CrO2 surface which enhances the CrO2 magnetoresistance and might be used as a barrier in magnetic tunnel junctions.

Half-metallic band structure observed in Co2MnSi-based magnetic tunnel junctions

2007 ◽  
Vol 40 (5) ◽  
pp. 1221-1227 ◽  
Author(s):  
Y Sakuraba ◽  
M Hattori ◽  
M Oogane ◽  
H Kubota ◽  
Y Ando ◽  
...  
Keyword(s):  
Band Structure ◽  
Tunnel Junctions ◽  
Magnetic Tunnel Junctions ◽  
Half Metallic

Inverse Magnetoresistance In Manganite/SrTiO3/Co Tunnel Junctions

1999 ◽  
Vol 574 ◽  
Author(s):  
J. M. De Teresa ◽  
A. Barthélémy ◽  
J. P. Contour ◽  
A. Fert ◽  
R. Lyonnet ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Fermi Level ◽  
Spin Polarization ◽  
Density Of States ◽  
High Magnetic Field ◽  
Applied Voltage ◽  
Tunnel Junctions ◽  
Effect Of Temperature ◽  
Half Metallic ◽  
Tunnel Magnetoresistance

AbstractIn La0.7Sr0.3MnO3/SrTiO3/Co tunnel junctions, the half-metallic nature of La0.7Sr0.3MnO3 allows probing the spin polarization of Co. For applied voltage bias around zero volts, an inverse tunnel magnetoresistance is found, indicating the negative spin polarization of Co at the Fermi level as expected from the density of states of the “d” band in Co. The bias dependence of the magnetoresistance reflects the structure of the “d” band density of states of Co. In this article we underline the important consequences for the knowledge of the spin-dependent tunneling in solids brought by these results and describe in detail the effect of temperature and high magnetic field on the magnetoresistance.

scholarly journals Superlattice-barrier magnetic tunnel junctions with half-metallic magnets

2020 ◽  
Vol 22 (9) ◽  
pp. 093005
Author(s):  
Peng Tseng ◽  
Zheng-Yi Chen ◽  
Wen-Jeng Hsueh
Keyword(s):  
Tunnel Junctions ◽  
Magnetic Tunnel Junctions ◽  
Half Metallic

scholarly journals Magnetic tunnel junctions consisting of a periodic grating barrier and two half-metallic electrodes

2019 ◽  
Vol 21 (12) ◽  
pp. 123006 ◽  
Author(s):  
Henan Fang ◽  
Mingwen Xiao ◽  
Yuanyuan Zhong ◽  
Wenbin Rui ◽  
Jun Du ◽  
...  
Keyword(s):  
Tunnel Junctions ◽  
Magnetic Tunnel Junctions ◽  
Half Metallic ◽  
Periodic Grating ◽  
Metallic Electrodes
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